Double Shield Of Wood Is A Plant Genetic Diversity In Issr Analysis

Dipelta, an endemic genus to China, belongs to the family Caprifoliaceae, comprised with four species: D. floribunda, D. elegans, D. yunnanensis, D. wenxianensis. Its distribution area extends from the southwest to central China, across Yunnan, Sichuan, Shaanxi,Gansu, Hubei, Hunan and Guizhou. In the Southwestern Gansu area distribute all species, D. elegans and D. wenxianensis are not only endemic in the region, but also rare and endangered species. Genetic diversity, genetic variation and differentiation of Dipelta have never been studied. Therefore,with the molecular markers, genetic background and evolutionary relationships among Dipelta spcecies would be detected, whih impplied for conservation of endangered plants.Using ISSR molecule markers, 6 populations in 4 species of Dipelta, including D. floribunda, D. elegans, D. yunnanensis, D. wenxianensis were adopted as materials to research the genetic diversity. Using 13 ISSR primers were amplified for 71 samples. The results of POPGENE analyze indicated that it was moderate level of the genetic diversity of Dipelta, mean PPB (percentage of polymorphic bands) h and I of 4 species of Dipelta as below: D.wenxianensis. (PPB=62.02%,h=0.1850,I=0.2826); D.yunnanensis (PPB=40.31%, h=0.1238, I=0.1874); D. floribunda (PPB=36.82%, h=0.1395,I=0.2045); D. elegans (PPB=15.51%, h=0.0583,I=0.0861). Genetic diversity in D.elegans is the lowest. It is possibly caused by the endemic distribution and local ecotope.The the highest genetic diversity of D. wenxianensis is possibly duo to the complex ecotope.Coefficient of population differentiation of Dipelta (Gst) was 0.2683, which indicated high genetic differentiation existed among spcecies. The dendrograms constructed on the basis fo Nei's genetic distance showed that close genetic relationships were revealed between D. wenxianensis and D. floribunda, and between D. yunnanensis and D. elegans.